By-products utilization: An integrated solution

The farming community regards agricultural wastes as resources. In addition to utilizing nutrient as fertilizer, green energy production is a well-known by-product. Examples include: anaerobic digestion (AD) of livestock manure to produce biogas for use as fuel for stove, boiler, combined heat and power (CHP) generation or even as vehicle fuel; and gasification of relatively dry wastes such as poultry manure, wood chips, and saw dust for power generation. Besides green energy, processing of agricultural waste can provide many additional benefits. Utilization of carbon dioxide from combustion exhaust in greenhouses is less commonly known, and the environmental benefits such as the reduction of pathogens, odour, greenhouse gas emission and water contamination are difficult to quantify. These benefits are discussed in greater detail in this paper, and quantification methods are proposed. The overall cost of agricultural waste management can be significantly reduced when "full-benefit" accounting is applied, and the cost of implementing advanced technologies can be justified. An integrated solution for agricultural, environmental, public health and energy concerns can be developed by fully utilizing the by-products. A recent case of locally initiated efforts in developing such an integrated solution for the rural community of Chatham-Kent in Ontario, Canada will be briefly described.